Semiconductor devices are ubiquitous in modern society and semiconductor manufacturers, for example manufacturers of solid state lighting devices, are constantly seeking to improve the performance of their products. Recently, light emitting devices based on gallium nitride (GaN) have found a wide range of application. In particular, high brightness LEDs based on GaN have been widely used, for example in backlighting of LCDs, traffic signals, full color displays and street lights. GaN LEDs have also recently started to enter the general lighting market.
In order to be more effective in general lighting applications, the performance of GaN LEDs should be further improved. Accordingly, there is a need for GaN LEDs having improved light extraction efficiency.